//零钱兑换
//https://leetcode.cn/problems/coin-change-ii/description/
class Solution {
public:
    int change(int amount, vector<int>& coins) 
    {
        int n = coins.size();
        vector<unsigned long long> dp(amount + 1);
        dp[0] = 1;

        for(int i = 1; i <= n; i++)
        {
            for(int j = coins[i - 1]; j <= amount; j++)
            {
                dp[j] = (dp[j] + dp[j - coins[i - 1]]);
            }
        }
        return dp[amount];
    }
};